CN101965522A - Method for Measuring SOC of a Battery in a Battery Management System and the Apparatus Thereof - Google Patents

Abstract

According to an embodiment of this invention, a method for measuring SOC (State Of Charge) of a battery comprises the steps of: obtaining current data, voltage data and temperature data by measuring the current, the voltage and the temperature of a battery,calculating SOCi (State of Charge based on current) by accumulating the current data,calculating open circuit voltage by using an equivalent circuit model which simply presents the current data, the voltage data and the battery through an electric circuit,calculating SOCv (State of Charge based on voltage) by using the temperature data and the open circuit voltage,and choosing at least one of the SOCi and the SOCv as SOC of the battery by using the SOCi and the SOCv based on the judgment on the current state of the battery for a certain time interval.

Description

In battery management system, measure the method and the device thereof of the charged state of battery

Technical field

The present invention relates in battery management system to measure method and the device thereof of the SOC (state of charging) of battery, relate more specifically to use the simple equivalent circuit in battery management system, SOCi (based on the charged state of electric current) or SOCv (based on the charged state of voltage) to be set to method and the device thereof of the SOC of battery according to the condition of hope.

Background technology

Automobile with the internal combustion engine that uses gasoline or heavy oil pollutes (as atmospheric pollution) and has and have a strong impact on producing usually.Therefore, in order to reduce the generation of pollution, made many effort and developed motor vehicle driven by mixed power or electric vehicle.

Recently, developed the high power secondary battery that uses high-energy-density, nonaqueous electrolyte.In order to form the high capacity secondary cell, a plurality of high power secondary batteries can be set and they are connected in series.

As mentioned above, the high capacity secondary cell (below, be called " battery ") normally form by a plurality of secondary cells that are connected in series.Concerning battery, especially HEV battery,, maintain suitable duty with the charging of control battery and discharge and with battery because a plurality of or dozens of secondary cell wheel current charge and discharge be necessary battery is managed.

The BMS (battery management system) of the whole states that are used to manage battery is provided for this reason.BMS detects voltage, electric current or temperature etc., estimates SOC and controls SOC to optimize the fuel consumption efficiency of vehicle by calculating operation.In order accurately to control SOC, need correctly measure the SOC of battery when carrying out charging and discharge work.

As prior art, there is disclosed korean patent application No.2005-00611234 (submission on July 7th, 2005), its exercise question is " Method for resetting SOC of secondary battery module ".

For the SOC of counting cell accurately, above-mentioned prior art comprises: current value, magnitude of voltage and the temperature value of measuring battery module when opening switch, use the value of measuring to calculate initial SOC, current value adds up, calculate actual SOC according to the current value that adds up, determine whether battery module is in no-load condition, determining if battery module is in no-load condition whether actual SOC is in can be by being provided with in the scope that the current value that adds up is measured, and if actual SOC be in outside the scope of setting then come to calculate SOC according to magnitude of voltage by the measuring voltage value.But the prior art is not open with method and the device thereof of simple equivalent circuit application in actual battery.

In general, in a short time, SOCi does not have error, still, as shown in Figure 1, exists the trend of error accumulation.Therefore, under the situation that battery works long hours, sizable error appears.Especially, when finishing the charge or discharge of battery fully, produce cumulative errors usually.This is caused by following reason: the sum of errors that degree of accuracy is reduced by the SOC that caused by self discharge to be produced has been ignored the error effect that the LBS position of CPU is produced when calculating SOC.In addition, because the degree of accuracy of SOC depends on current metering sensor widely, therefore can not correction error when sensor has fault.

But as shown in Figure 2, SOCv measures SOC by open-circuit voltage.In this measuring method, when not flowing, electric current can obtain point-device result.But when electric current flowed, the degree of accuracy of SOCv depended on the charging and the discharge mode of battery.Therefore, because the degree of accuracy of SOC also depends on charging and discharge mode, the deterioration so it becomes.In addition, make in the usable range that charging that the degree of accuracy of SOCv worsens and discharge mode be in common batteries.Thereby, although only use SOCv, also there is the problem that must accept sizable error.

Summary of the invention

An object of the present invention is to provide a kind of method and device thereof of measuring the SOC (charged state) of battery in battery management system, it uses simple equivalent circuit model and adaptive digital filter, thereby measures the SOC of battery easily and accurately.

Another object of the present invention provides a kind of method and device thereof of measuring the SOC (charged state) of battery in battery management system, it determines whether low current condition has kept the time period of expectation then SOCi (based on the charged state of electric current) or SOCv (based on the charged state of voltage) to be set to the SOC of battery, thereby measures the SOC of battery easily and accurately.

For realizing purpose of the present invention, the invention provides a kind of method of measuring the charged state of battery, this method comprises: obtain current data, voltage data and temperature data by electric current, voltage and the temperature of measuring battery; By the current data that adds up, calculate SOCi (based on the charged state of electric current); Use equivalent-circuit model to calculate OCV (open-circuit voltage), in this equivalence circuit model, represent current data, voltage data and battery simply by circuit; Serviceability temperature data and OCV calculate SOCv (based on the charged state of voltage); And the current status of in the time period of expectation, judging battery, and use SOCv and SOCi at least one the SOC of battery is set.

In addition, the invention provides a kind of device of measuring the SOC of battery, this device comprises: the battery information acquisition unit, and it measures electric current, voltage and the temperature of battery, and obtains current data, voltage data and temperature data; The electric current portion that adds up, it calculates SOCi by the current data that adds up; The OCV calculating part, it uses equivalent-circuit model to calculate OCV, represents current data, voltage data and battery simply by circuit in this equivalence circuit model; SOCv estimation portion, its serviceability temperature data and OCV estimate SOCv; And SOC is provided with portion, and it judges the current status of battery in the time period of expectation, and use SOCv and SOCi at least one the SOC of battery is set.

The present invention measures the SOC of battery easily and accurately by using simple equivalent circuit model and adaptive digital filter.

In addition, the present invention determines whether low current condition has kept the time period of expectation, uses among SOCv and the SOCi at least one that the SOC of battery is set then, thereby measures the SOC of battery easily and accurately.

Description of drawings

According to the following description to preferred implementation that provides in conjunction with the accompanying drawings, above-mentioned and other purposes, feature and advantage of the present invention will become obviously, in the accompanying drawings:

Fig. 1 shows by using conventional SOCi that the figure of situation of the SOC of battery is set.

Fig. 2 illustrates by using conventional SOCv that the synoptic diagram of situation of the SOC of battery is set.

Fig. 3 is the block diagram according to the device of the SOC of the measurement battery of embodiment of the present invention.

Fig. 4 is the process flow diagram according to the method for the SOC of the measurement battery of embodiment of the present invention.

Fig. 5 shows the figure according to the simulation result under the situation of the side-play amount of the appearance 1A of embodiment of the present invention.

Fig. 6 shows the view according to the equivalent-circuit model of embodiment of the present invention.

Fig. 7 shows and provides actual SOC under the situation of model of storage effect and the figure of the BMS SOC that calculates according to embodiment of the present invention in use.

Fig. 8 shows and provides the figure of the compensation point under the situation of model of storage effect according to embodiment of the present invention in use.

Fig. 9 shows the view of the equivalent-circuit model of another embodiment according to the present invention.

Figure 10 shows the figure according to the time standard of the proposal of embodiment of the present invention.

Figure 11 shows the figure that has the error under the situation of emulation of time standard of 20 seconds time standard and proposal in execution according to embodiment of the present invention.

[detailed description of critical piece]

100: the electric current portion that adds up

200: low-pass filtering portion

300: the open-circuit voltage calculating part

400:SOCv estimation portion

500:SOC is provided with portion

Embodiment

The various terms that use in the application are generally described in the art, but under special circumstances, some terms are selected by the applicant alternatively.In this case, in instructions of the present invention, defined the implication of these terms.Therefore, the present invention should understand according to implication rather than its title of term.

Below, will describe embodiments of the present invention with reference to the accompanying drawings in detail.

Fig. 3 is the block diagram of device that is used to measure the SOC of battery according to embodiment of the present invention in battery management system.With reference to figure 3, the device that is used to measure the SOC of battery comprises that add up portion 100, low-pass filtering portion 200, open-circuit voltage calculating part 300, SOCv estimation portion 400 and SOC of battery information acquisition unit (not shown), electric current is provided with portion 500.

The processing of the SOC of counting cell in battery management system (hereinafter referred to as " BMS SOC ") comprises following 6 steps:

First step: collected current and voltage data

Second step: by electric current accumulation calculating SOCi

Third step: low-pass filtering

The 4th step: equivalent-circuit model and adaptive digital filtering

The 5th step: by open-circuit voltage and temperature computation SOCv

The 6th step: suitably select SOC.

The battery information acquisition unit is carried out first step.That is, the battery information acquisition unit is from battery management system (BMS:Battery Management System) collected current data, voltage data and temperature data etc.The current data of collecting is transferred to the electric current portion 100 that adds up.In electric current added up portion 100, the current data that adds up also then was added to the SOC (SOC among Fig. 3 (k-1)) that calculates in the last time interval with current data, calculates SOCi thus.

In addition, current data and the voltage data of being collected by the battery information acquisition unit is transferred to low-pass filtering portion 200.200 pairs of current data of low-pass filtering portion and voltage data carry out filtering and then they are transferred to open-circuit voltage calculating part 300.Open-circuit voltage calculating part 300 calculates the parameter of using by equivalent-circuit model and adaptive digital filtering in equivalent-circuit model, and then uses these parameters to calculate open-circuit voltage (OCV:Open Circuit Voltage).SOCv estimation portion 400 serviceability temperature data and this OCV estimate SOCv, and then the SOCv that estimates is transferred to SOC is provided with portion 500.SOC is provided with portion 500 and will be provided with to BMSBOC at the add up SOCi that portion 100 calculates or the SOCv that estimates in SOCv estimation portion 400 of electric current according to predetermined standard.Be described in the detailed process of carrying out in the various piece of SOC measurement mechanism below with reference to Fig. 5 to Figure 10.

Fig. 4 is the process flow diagram according to the method for the SOC of the measurement battery of embodiment of the present invention.With using the SOC measurement mechanism in Fig. 3 the SOC measuring method is described.

With reference to figure 4, the battery information acquisition unit is measured (S401) such as current data, voltage data and temperature datas from the electric battery of BMS in real time.And electric current the add up current data and calculate SOCi (S402) of portion 100 that adds up.Then, 200 pairs of current data of low-pass filtering portion and voltage data carry out filtering (S403).

Filtered current data and voltage data are transferred to OCV calculating part 300, and OCV calculating part 300 calculates the parameter (S404) use by adaptive digital filtering in the equivalent electrical circuit module, and use these parameters to calculate OCV Vo (S405).In addition, SOCv estimation portion 400 uses this OCV to estimate SOCv (S406).

Then, SOC is provided with portion 500 and determines whether to remain on low current condition.If remain on low current condition (S407), then SOCv is provided with to BMS SOC (S408), and if do not remain on low current condition (S407), then SOCi is provided with to BMS SOC (S409).Come the SOC (S410) of battery in the counting cell management system by above-mentioned processing.Below, with each step that is described in detail in the BMS SOC measuring method.

A, first step: collected current data, voltage data and temperature data etc.

This step is from BMS collected current data and voltage data etc.In this step, because the fault of current sensor may accurately not measured current data.Specifically, accurately do not measure strength of current at current sensor but only measure under the situation of its value roughly, in electric current is estimated to handle, sizable error may occur.But, in SOC measuring method of the present invention, compensate the error of SOCi with SOCv.Check by actual emulation whether SOC measuring method of the present invention has calculated BMS SOC exactly.As a result,, but utilize SOCv to compensate, so when calculating final BMS SOC, do not have problem because error builds up in SOCi.Confirmed that error between calculated value and the actual value is in 5.000% the target tolerance limit, this target of 5.000% is allowed and is limited to 1.502～-4.170%.That is,, in SOC measuring method of the present invention, there is not big error although can not accurately measure electric current owing to the fault of current sensor.Except the fault of current sensor, also other problems may appear.Current value can be offset owing to the fault of current sensor or the fault of CAN (controller local area network), and then is transmitted.

Fig. 5 is the figure that illustrates according to the simulation result under the situation of the side-play amount of the appearance 1A of embodiment of the present invention.As shown in Figure 5, error is accumulated in SOCi.Should be understood that the degree of accumulation is very big.Accumulation causes by being offset 1A, and calculates this accumulation.But, it is to be further understood that the SOCv compensation suitably produces, thereby error occurs indistinctively.

According to whole analysis,, therefore in BMS SOC, may have problems owing to do not have the SOCv compensation at the beginning and the latter end (charging and discharge operation wherein occurring) of pattern.But,, then can guarantee computation's reliability if after charging and discharge operation, carried out the SOCv compensation.In addition, under the situation of the side-play amount of appearance-1A, can guarantee its reliability in the same way.

B, second step: add up by electric current and to calculate SOCi

In this step, the current data of collecting in the first step is added up and then be added on the SOC that calculates in the last time interval, calculate SOCi thus.By being carried out integration in time, electric current carries out this calculating.Result calculated is recently represented remaining capacity with percentage then divided by total capacity.This can be represented by following equation (1):

Equation 1

In SOC measuring method of the present invention, because per second all detects electric current, equation 1 can be by equation 2 expressions

Equation 2

${\mathrm{SOC}}_i\left(k\right)=\mathrm{SOC}(k-1)+\frac{1}{Q_{\max }}\·I\left(k\right)\·t$

That is, be added to SOC among the step k-1 and carry out among the step k calculating SOCi by the SOC that will increase.The SOC of this increase be the electric current that in step k, flows and interval time t multiply each other and divided by total capacity Qmax.

C, third step: low-pass filtering

Make current data and the voltage data in first step, collected pass through low-pass filter.It is 0.6 that the present invention adopts third-order low-pass filter and filter constants f.But, the invention is not restricted to this condition, and can use wave filter and other filter constants of other types.The wave filter of Shi Yonging can be expressed as the form of following equation 3 in the present invention:

Equation 3

gi(n)＝f ³i+3(1-f)gi(n-1)+3(1-f) ²gi(n-2)+(1-f) ³gi(n-3)

In SOC measuring method of the present invention, exist the 6 kinds of current data altogether and the voltage data that in equivalent-circuit model, need.The current data former state is used, and voltage data uses and the difference of initial value.The second-order differential value of the differential value of current value, electric current and electric current forms one group of current data.Difference between initial voltage value and the current magnitude of voltage, its single order differential value and its second-order differential value form one group of voltage data.In to the description of equivalent-circuit model, will fully be described as the reason what needs differentiated data and voltage difference.

D, the 4th step: equivalent-circuit model and adaptive digital filtering

Equivalent-circuit model can be implemented as two models according to the embodiment of the present invention.In other words, equivalent-circuit model can be implemented as first equivalent-circuit model and second equivalent-circuit model of each embodiment according to the present invention.Below, will describe first equivalent-circuit model and will describe second equivalent-circuit model with reference to figure 6 to Fig. 8 with reference to figure 9.

1) first equivalent-circuit model

(1) first equivalent-circuit model

In this step, will be applied to battery model at current data and the voltage data that third step is collected, to obtain OCV (open-circuit voltage).This is owing to can obtain SOCv by this OCV.As battery model, thermal behavior in the existence consideration battery and first principle model of electrochemical phenomena.But owing to need too much time and expense to develop above-mentioned model, the battery model among the present invention is by being realized by the equivalent-circuit model of the simple expression of circuit.

Modeling to as if lithium polymer battery (LiPB), and circuit model is made up of first model.Fig. 6 is the view that illustrates according to the equivalent-circuit model of embodiment of the present invention.SOC measuring method of the present invention is used the equivalent-circuit model of being represented by ball bearing made using.Included each element such as resistor and capacitor has the implication shown in following table 1 in the equivalent-circuit model:

Table 1

The element of equivalent-circuit model

Stage

Process

I	Electric current (charging: (+)/discharge (-))
		V	Terminal voltage
V o	Open-circuit voltage (OCV)
		R 1	The lump interface resistance
R 2	The lump resistance in series
		C	Electric double layer capacitance

In Fig. 6, R ₂Be the resistance in the electrode, and R ₁And C is resistance and the electric capacity that is illustrated in the electrostatic double layer that produces at the interface between an electrode and another electrode or the dividing plate.Usually, obtain the numerical value of each parameter by first principle model or experiment.The equivalent-circuit model of Fig. 6 can be represented by following equation 4:

Equation 4

$\mathrm{\&Delta;V}={\mathrm{\&Delta;<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">R</figure-callout>}}_2+{\mathrm{CR}}_1{R}_2\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">s</figure-callout>}}{1+{\mathrm{CR}}_{1}s}\right)I$

In equation 4, be understandable that, by obtaining to obtain OCV with each the element corresponding parameter that forms equivalent-circuit model.In other words, be to obtain OCV according to a target of battery modeling of the present invention by obtaining each parameter and substitution obtained in equation 4 parameter.

Can derive equation 4 by following processing.In the equivalent-circuit model of Fig. 6, can represent electric current according to the form of equation 5 by Kirchhoff's law.

Equation 5

I+I ₂+I ₃＝0

In addition, when setting up model when the value of considering resistance in entire circuit and capacitor, model can be by equation 6 expressions.

Equation 6

V＝V ₀+IR ₂-I ₃R ₁

$V={\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+{\mathrm{IR}}_2-\frac{Q}{C}$

$I_2=\frac{\mathrm{dQ}}{\mathrm{dt}}$

Herein, when using when representing voltage and this OCV with the difference of initial value (t=0), it can be represented by equation 7.

Equation 7

ΔV＝V(t)-V(0)

ΔV ₀＝V ₀(t)-V ₀(0)

If consider Δ V ₀=V ₀(t)-V ₀(0) put equation 7 in order, then it can be expressed as equation 8.

Equation 8

ΔV＝ΔV ₀+IR ₂-I ₃R ₁

$\mathrm{\&Delta;V}={\mathrm{\&Delta;<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+{\mathrm{IR}}_2-\frac{Q}{C}$

If equation 8 is taken at temporal differential and arrangement then, then it can be expressed as equation 9.

Equation 9

$\frac{d(\mathrm{\&Delta;V}-{\mathrm{\&Delta;V}}_0)}{\mathrm{dt}}+\frac{1}{{\mathrm{CR}}_1}(\mathrm{\&Delta;V}-{\mathrm{\&Delta;V}}_0)=\frac{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}{{\mathrm{CR}}_1}I+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\frac{\mathrm{dI}}{\mathrm{dt}}+\frac{I}{C}$

Then, if use Laplace transform it is changed, then it can be expressed as equation 10.

Equation 10

$\mathrm{\&Delta;V}={\mathrm{\&Delta;<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">R</figure-callout>}}_2+{\mathrm{CR}}_1{R}_2\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">s</figure-callout>}}{1+{\mathrm{CR}}_{1}s}\right)I$

Here, suppose that the variable quantity in the electric current is proportional with variable quantity in OCV, and proportionality constant is h, then can sets up following equation:

${\mathrm{\&Delta;<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0=\frac{h}{s}I$

If in this equation substitution equation 10, then equation 10 can be expressed as equation 11.

Equation 11

$\mathrm{\&Delta;V}=\frac{({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+R_2)s+{\mathrm{<figure-callout\; id="1"\; label="CR"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">CR</figure-callout>}}_1\mathrm{hs}+h+{\mathrm{CR}}_1{R}_2{s}^2}{(1+{\mathrm{CR}}_{1}s)s}I$

Here, each factor can be limited by equation 12.

Equation 12

ΔV＝V ₁ I＝I ₂

sΔV＝V ₂ sI＝I ₂

s ²ΔV＝V ₂ s ²I＝I ₃

If in the factor substitution equation 11 that limits, then equation 11 can be expressed as equation 13.

Equation 13

V ₂＝-CR ₁V ₃+CR ₁R ₂I ₃+(R ₁+R ₂+CR ₁h)I ₂+hI ₁

If equation 13 is expressed as the form of matrix, then equation 13 can be expressed as equation 14.

Equation 14

${\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_2=\left[\begin{array}{cccc}{V}_3& I_3& I_2& I_1\end{array}\right]\left[\begin{array}{c}{-\mathrm{<figure-callout\; id="1"\; label="CR"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">CR</figure-callout>}}_1\\ {\mathrm{CR}}_1{R}_2\\ {\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">R</figure-callout>}}_2+{\mathrm{CR}}_{1}h\\ h\end{array}\right]$

Here, relevant with electric current and the voltage factor can obtain by and current data and voltage data carried out filtering third step that collect from BMS.By the factor that substitution obtained and use adaptive digital filter to obtain each parameters R ₁, R ₂, C, h.The method of using adaptive digital filter will be described after a while.If obtained the parameter relevant with each situation by wave filter, then with in their substitution equatioies 15, equation 15 is the basic equatioies that are used to calculate OCV.

Equation 15

ΔV ₀+CR ₁sΔV ₀＝V ₁+CR ₁V ₂-CR ₁R ₂I ₂-(R ₁+R ₂)I ₁

${\mathrm{\&Delta;<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0=\frac{{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">V</figure-callout>}}_1+{\mathrm{CR}}_1{V}_2-{\mathrm{CR}}_1{R}_2{I}_2-({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+R_2)I_1}{1+{\mathrm{CR}}_{1}s}$

Be used for calculating SOCv by the OCV that uses equation 15 to obtain at next step.

SOC measuring method of the present invention is used above-mentioned equivalent-circuit model.But,, then can obtain equation 16 if the equation of deriving from this model is further carried out integration by a step.

Equation 16

$\mathrm{\&Delta;V}=\frac{{\mathrm{CR}}_1{R}_{2}s+({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+R_2)+h/s+{\mathrm{CR}}_{1}h}{{\mathrm{CR}}_{1}s+1}I$

By with the denominator of original equation and molecule divided by s, can obtain storage effect.Fig. 7 shows actual SOC and the BMS SOC that calculates under the situation of using the model that storage effect is provided, and Fig. 8 shows the figure of compensation point under the situation of using the model that storage effect is provided.

Under the situation of using equivalent-circuit model of the present invention, compensation suitably appears generally.If use the model that storage effect is provided, compensation then further appears continually.In addition,, then further produce noise, especially further produce noise at the part place that compensation occurs if use the model that storage effect is provided.This means that data become unstable generally when carrying out integration.But, because the unstable degree of data is not high, so can use the model that storage effect is provided.Using equivalent-circuit model of the present invention is most preferred basically, but if necessary, then can use the model that storage effect is provided.

(2) adaptive digital filter

As equation 14, can represent equivalent-circuit model with the form of matrix.In equation 14, suppose Be w, and Be θ, equation 14 can be expressed as equation 17.

Equation 17

V ₂＝w ^-1θ

In this matrix, obtain w by making current data and voltage data through the third step of low-pass filter, and V ₂Also obtain by identical result.The purpose of adaptive digital filter is to obtain matrix θ by these two values, and estimates to pass through in real time the parameter value of each element.Suppose through the V behind the low-pass filter ₂Be gV ₂, equation 17 can be expressed as equation 18.

Equation 18

gV ₂＝w ^-1θ

At first, by not having electric current to flow and voltage has under the original state of OCV value and obtains parameter value, with in this parameter value substitution equation 18, obtain the initial value of matrix θ then.The matrix of this moment is by θ ₀Expression.The table of squares of matrix is shown equation 19.

Equation 19

P ₀＝θ ₀ ²

Here, the required matrix K of continuous updating matrix θ can be defined as equation 20.

Equation 20

$K=\frac{{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}{R+w^{-1}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}$

Wherein, R is in order to prevent because of gV ₂The denominator that causes of initial value be 0 to disperse the value of determining, and should value very little.Matrix can be grouped as equation 21.

Equation 21

$K=\frac{{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}{R+w^{-1}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}=\frac{{\mathrm{gV}}_2(n-1)\&CenterDot;{\mathrm{\&theta;}}_0}{R+{\left\{{\mathrm{gV}}_2(n-1)\right\}}^2}$

GV wherein ₂(n-1) be gV ₂Tight previous value.By the proportionate relationship of similar equation 22 matrix θ is carried out continuous updating.

Equation 22

$\frac{\mathrm{\&theta;}}{{\mathrm{gV}}_2\left(n\right)}=\frac{{\mathrm{\&theta;}}_0}{{\mathrm{gV}}_2(n-1)}$

Equation 22 can be organized into equation 23.

Equation 23

$\mathrm{\&theta;}={\mathrm{\&theta;}}_0-[\frac{{\mathrm{gV}}_2(n-1)\&CenterDot;{\mathrm{\&theta;}}_0}{{\left\{{\mathrm{gV}}_2(n-1)\right\}}^2}\&CenterDot;\{{\mathrm{gV}}_2(n-1)-{\mathrm{gV}}_2\left(n\right)\left\}\right]$

Because R is very little, can be with the matrix K substitution.This is grouped as equation 24.

Equation 24

θ＝θ ₀-[K·{gV ₂(n-1)-gV ₂(n)}]

If in relational expression substitution equation 24, then equation 24 can be expressed as equation 25.

Equation 25

θ＝θ ₀-[K·{w ^-1·θ ₀-gV ₂(n)}]

The value that can come θ in the calculation equation 25 by current data, voltage data and last matrix θ.Therefore, can estimate each parameter continuously.After the starting stage, upgrade matrix θ and matrix P with the value of new calculating.Then, calculate OCV by the parameter that obtains.

2) second equivalent-circuit model

(1) second equivalent-circuit model

Below, with second equivalent-circuit model and the adaptive digital filtering method that is described with reference to Figure 9 according to second embodiment of the invention.

Second equivalent-circuit model and adaptive digital filtering method according to second embodiment of the invention provide discrete equivalent electrical circuit modeling method by the characteristic of using BMS to receive magnitude of voltage, current value and the temperature value of battery discretely.As a kind of model of simplification, represent electrochemical properties in the battery simply according to second equivalent-circuit model of second embodiment of the invention.Therefore, owing to can easily design a model and make the modeling required time period of operation to minimize, so it is applicable to BMS.

Fig. 9 shows the view of the equivalent-circuit model of another embodiment according to the present invention.

Provide second equivalent-circuit model according to second embodiment of the invention as a model.Each element such as resistance, capacitor etc. in the model has self implication as being shown in the following Table 2:

Table 2

The element of equivalent-circuit model

Stage	Process
		I	Electric current (charging: (+)/discharge (-))
V	Terminal voltage
		V 0	Open-circuit voltage (OCV)
R 0	The lump interface resistance
		R	The lump resistance in series
C	Double layer capacitor

In Fig. 9, as shown in the table 2, R ₀Be the resistance in the electrode, and R and C be resistance and the electric capacity that is illustrated in the electrostatic double layer that produces at the interface between an electrode and another electrode or the dividing plate, and V ₀Be the OCV of battery.

Key issue in application thought is with Fixed Time Interval current data and voltage data to be input to BMS discretely in second equivalent-circuit model.Owing to such core concept, can realize representing the model of the behavior of battery by second equivalent-circuit model.The parameter of using in this model is calculated by adaptive digital filter.

Provide equation 26 to 29 by Fig. 9 and table 2.

Equation 26

I+I ₂+I ₃＝0

Equation 27

V＝V ₀+IR ₀-I ₃R

Equation 28

$V={\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+{\mathrm{IR}}_0-\frac{Q}{C}$

Equation 29

$I_2=\frac{\mathrm{dQ}}{\mathrm{dt}}$

By equation 28 is carried out integration in time, put in order then, equation 30 is provided.

Equation 30

$\frac{d}{\mathrm{dt}}\left({V-V}_0\right)+\frac{1}{\mathrm{RC}}\left({V-V}_0\right)=\frac{1}{C}(1+\frac{R_0}{R})+{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">R</figure-callout>}}_0\frac{\mathrm{dI}}{\mathrm{dt}}$

Provide equation 31 by using integrating factor that equation 30 is differentiated in time.

Equation 31

$V=\frac{Q\left(0\right)}{C}{e}^{-t/\mathrm{RC}}+{\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0+\frac{1}{C}{\&Integral;}_{\mathrm{\&xi;}=0}^{\mathrm{\&xi;}=t}\left(I\left(\mathrm{\&xi;}\right)e^{--(t-\mathrm{\&xi;})/\mathrm{RC}}\right)\mathrm{d\&xi;}$

Suppose polarization phenomena in battery, not occur, then Q (0)=0 at the initial time of BMS operation.Therefore, equation 31 can be expressed as equation 32.

Equation 32

$V={\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0+\frac{1}{C}{\&Integral;}_{\mathrm{\&xi;}=0}^{\mathrm{\&xi;}=t}\left(I\left(\mathrm{\&xi;}\right)e^{--(t-\mathrm{\&xi;})/\mathrm{RC}}\right)\mathrm{d\&xi;}$

In equation 32, because current data and voltage data are input to BMS at interval according to regular time, so can represent current data and voltage data discretely.Data input time is Δ t at interval.

Under the situation of t≤0, suppose I (t)=0 and T=0, it can be expressed as

${\&Integral;}_0^0\left(I\left(\mathrm{\&xi;}\right)e^{--(t-\mathrm{\&xi;})/\mathrm{RC}}\right)\mathrm{d\&xi;}=0$

Therefore, equation 32 can be expressed as equation 33.

Equation 33

V-V ₀-IR ₀| _t＝0＝0

In addition, at t=Δ t=t1, promptly pass through under the situation of Δ t time period, can equation 32 be expressed as equation 34 by skew integration.

Equation 34

${V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{t={\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">t</figure-callout>}}_1}\&ap;\frac{e^{-{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">t</figure-callout>}}_1/\mathrm{RC}}}{C}(I\left(t_1\right)\mathrm{\&Delta;t}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="e\; t"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{t_{}})$

In addition, at t=2 Δ t=t2, promptly, can equation 32 be expressed as equation 35 by skew integration through associating t1 under the situation of the time period of Δ t.

Equation 35

${V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{t=\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">t</figure-callout>}2}\&ap;\frac{e^{-{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">t</figure-callout>}}_2/\mathrm{RC}}}{C}[(I\left(t_2\right)\mathrm{\&Delta;t}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="e\; t"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">e</figure-callout>}}^{t_{}})+(I\left(t_1\right)\mathrm{\&Delta;t}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="e\; t"\; filenames="HPA00001216715800021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{t_{}})]$

Equation 34 and 35 can be combined as equation 36.

Equation 36

${V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{t={\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HPA00001216715800061.png,HPA00001216715800071.png"\; state="\{\{state\}\}">t</figure-callout>}}_2}\&ap;\frac{I\left(t_2\right)\mathrm{\&Delta;t}}{C}+e^{-\mathrm{\&Delta;t}/\mathrm{RC}}[{V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{t=t_1}]$

By repeating aforementioned calculation, with respect to time period t, equation 32 can be expressed as equation 37.

Equation 37

${V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_t\&ap;\frac{\mathrm{I\&Delta;t}}{C}+e^{-\mathrm{\&Delta;t}/\mathrm{RC}}[{V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{t-\mathrm{\&Delta;t}}]$

Therefore, calculate equivalent-circuit model by equation 38.

Equation 38

$V={\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0+{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0+\frac{1}{C}\mathrm{I\&Delta;t}+e^{-\mathrm{\&Delta;t}/\mathrm{RC}}[{V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{t-\mathrm{\&Delta;t}}]$

In equation 38, Δ t is data intervals input time, and t-Δ t is the parameter value in the last time interval.Suppose α=1/C and β=1/RC, equation 38 can be put in order simply is equation 39.

Equation 39

V＝V ₀+IR ₀+αIΔt+exp(-βΔt)[V-V ₀-IR ₀| _t-Δt]

In equation 39, β is a time constant, and τ is reciprocal and the time of expression battery when arriving normal condition.In general, under the situation through 3 τ or more battery operating time, the reaction in the estimating battery arrives normal condition.Also then calculate from the factor of BMS collected current and voltage by filtered electric current and voltage data.And, calculate VOC by each parameter of substitution.

The R0 of the Ohmage of expression battery self determines a fixed value according to properties of materials in the battery.Usually, can easily obtain this value by impedance.Be optimized having made up parameters R relevant and variable α and the β of C by adaptive digital filter with polarization.

(2) adaptive digital filter

Mathematically the equation 39 of the equivalent-circuit model of presentation graphs 9 can be expressed as equation 40 according to determinant.

Equation 40

$V=\left[\begin{array}{cccc}{\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">V</figure-callout>}}_0& {\mathrm{IR}}_0& I& {V-V}_0-{\mathrm{<figure-callout\; id="0"\; label="IR"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">IR</figure-callout>}}_0{|}_{n-1}\end{array}\right]\left[\begin{array}{c}1\\ 1\\ \mathrm{\&alpha;\&Delta;t}\\ \exp (-\mathrm{\&beta;\&Delta;t})\end{array}\right]$

In equation 40,

Situation under, equation 40 can be expressed as equation 41.

Equation 41

V＝w ^Tθ

In equation 41, calculate w by current data and voltage data, and also calculate v by current data and voltage data.Sef-adapting filter calculates θ by w and these two values of v, and comes estimated parameter value in real time by each component of θ.

Suppose that the V through low-pass filter is gV, equation 41 can be expressed as equation 42.

Equation 42

gV＝w ^Tθ

By calculating at t=0, promptly there is not electric current to flow through and voltage has parameter under the state of OCV value, obtain the initial value of θ.The matrix of this moment is θ ₀

θ ₀Multiply by θ ₀Equal equation 43.

Equation 43

P ₀＝θ ₀·θ ₀ ^T

In equation 43, upgrade the needed matrix k of θ continuously and may be defined as equation 44.

Equation 44

$K=\frac{{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}{r+w^T\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}$

In equation 44, r be for prevent denominator owing to V disperses defined constant, and have little value usually.Can it be become equation 45 by the matrix of arrangement equation 44.

Equation 45

$K=\frac{{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}{r+w^T\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HPA00001216715800071.png"\; state="\{\{state\}\}">P</figure-callout>}}_0\&CenterDot;w}=\frac{\mathrm{gV}(n-1)\&CenterDot;{\mathrm{\&theta;}}_0}{r+{\left\{\mathrm{gV}(n-1)\right\}}^2}$

In equation 45, gV (n-1) is the tight previous value of gV.Suppose that the continuous renewal to θ appears in proportionate relationship by equation 46, can be equation 47 with equation 46 arrangements.

Equation 46

$\frac{\mathrm{\&theta;}}{\mathrm{gV}\left(n\right)}=\frac{{\mathrm{\&theta;}}_0}{\mathrm{gV}(n-1)}$

Equation 47

$\mathrm{\&theta;}={\mathrm{\&theta;}}_0=[\frac{\mathrm{gV}(n-1)\&CenterDot;{\mathrm{\&theta;}}_0}{{\left\{\mathrm{gV}(n-1)\right\}}^2}\&CenterDot;\{\mathrm{gV}(n-1)-\mathrm{gV}\left(n\right)\left\}\right]$

Because r is very little value, therefore can be with in the K substitution equation 47.That is, equation 45 and equation 47 can be merged into equation 48.

Equation 48

θ＝θ ₀-[K·{gV(n-1)-gV(n)}]

By equation 42 is updated to equation 48, can obtain equation 49.

Equation 49

θ＝θ ₀＝[K·{w ^T·θ ₀-gV(n)}]

Primary variables in equation 49 is by current data, voltage data and θ ₀And obtain.Therefore, estimate each parameter continuously according to same way as.

In addition, after the starting stage, θ and P can be updated to new value.Thereby, can upgrade the parameter value that is suitable for equivalent-circuit model continuously.In addition, can use the parameter that obtains according to same way as to calculate OCV.

E, the 5th step: calculate SOCv by open-circuit voltage and temperature.

Calculate the value of OCV by equivalent-circuit model according to the present invention.In general, SOCv is subjected to OCV and Temperature Influence, and thereby is represented by the function between them.At room temperature, the relation between OCV and the SOCv equals equation 50.

Equation 50

SOC _v(n)＝-539.069·V ₀(n) ⁴+7928.96·V ₀(n) ³-43513.3·V ₀(n) ²

+105698·V ₀(n)-95954.8

As mentioned above, can obtain SOCv by the value of relation between OCV and the SOCv and OCV at room temperature.But, in equation 50, have a problem.Because it is the model under the room temperature, so error can occur when temperature variation.Maximal value and minimum value when the error that also produces when carrying out emulation under 45 to-10 ℃ the temperature except 25 ℃ of room temperatures have been described in table 3.

Table 3

The minimum and maximum error of each temperature simulation

Therefore, use the relation between the SOCv and OCV at room temperature, can obtain the exact value when 45 ℃ temperature.But, be understood that these values are incorrect when-10 ℃ temperature.In other words, when-10 ℃ temperature, need to use other relations or introducing to consider the factor of temperature.At first, the relation between SOCv and the OCV is represented by equation 51 when-10 ℃ temperature.

Equation 51

SOC _v(n)＝-425.6·V ₀(n) ⁴+6207·V ₀(n) ³-33740·V ₀(n) ²

+81113·V ₀(n)-72826

F, the 6th step: suitably select SOC

In the 6th step, which is selected SOCi that decision obtains from step before and the SOCv.Under the situation of low current condition, known SOCv has value accurately.Therefore, under low current condition, use SOCv.And under other state,, carry out this calculating by current value being added to tight last SOC.

In the criterion of low current condition, in the time period of expectation, continue to flow if having the following electric current of the absolute value of hope, then be defined as low current condition.Here, the absolute value of electric current and electric current flowing time are important criterion.Absolute value and time preferably are respectively 2A and 20 to 60s.

Under the situation of absolute value greater than 2A of strength of current, the criterion of low current condition is pine considerably, and it is judged as such state: flow through even also be judged as low current in the interval that does not have electric current to flow through.As a result, be difficult to accurately estimate SOCv, and thereby carry out SOCv compensation too continually.But, under the situation of absolute value less than 2A of electric current, when skew has taken place, can't discern low current.Therefore, preferably standard is set to 2A.

The standard of judging the electric current flowing time is more complicated.Suppose that when and electric current that have intensity 2A below corresponding with battery charge or discharge continue the mobile time period be t, this standard can be as represented in the table 4.

Table 4

Time scale standard at the SOCv compensation

The duration standard	Judge
		t＜a	Use SOCi
a≤t＜b	When the interval end of low current, compensate with SOCi
		b≤t	At the b time point of second, carry out the SOCv compensation

Figure 10 shows time standard.With reference to Figure 10, if low current flows and to reach 20 seconds or still less, by electric current accumulation calculating SOC.But, if flowing, low current reaches 20 seconds or more, then carry out the SOCv compensation.Time point when the low current with 2A or littler intensity is partly finished is carried out the SOCv compensation.But, if flowing, low current reaches 60 seconds or more, then carry out the SOCv compensation at 60 seconds time point.And, calculate low current once more and continue the mobile time period in the moment that compensation occurs.

By selecting the optimal time standard to determine this standard according to various emulation.Minimum 20 seconds time standard is based on such fact and decides: also can compensate even current sensor has fault.In fact, change in time standard under 10 seconds the situation, 8.3% error occurs.In addition, be set in the duration section under 60 the situation, last/following pattern place can not correctly compensate, and error accumulation.

Permission time standard movably main cause is to prevent because the increase of the error that incorrect compensation is caused after the long-time section charging of battery.The invention is not restricted to this time standard, and can comprise various time standards.

Among Figure 11 (a) to show in the execution time standard be error under 20 seconds the situation of emulation, and (b) shows in execution and has error under the situation of emulation of time standard of proposal among Figure 11.

With reference to Figure 11, the effectiveness of the time standard of proposing will be understood.Be under 20 seconds the situation of emulation, to should be understood that in time standard, sizable error occur at the beginning and the latter end that are right after after charging.But, under the situation of the emulation of time standard, begin error not occur with latter end at this with proposal.Whole error span is almost constant, but the error that the time point when charging is finished occurs has reduced by 1.5% or more.

The time standard of this proposal is more effective under the low temperature state.Under the situation of low temperature state, this time standard is effectively on the whole, and certainly, it also is effective for the time point when finishing charging.Under the situation of the time standard of use proposing, the maximal value of error is reduced to 3.542% from 7.287%, and its minimum value narrows down to-3.870% from-4.191%.This time standard that shows this proposal is more effective under the low temperature state.

If based on aforesaid time and current standard and be judged as low current condition, then SOCv is set to SOC.Otherwise the SOC measuring method of the application of the invention is accurately calculated BMS BOC.

Although described the present invention with respect to embodiment, it will be apparent to one skilled in the art that under the situation of the spirit and scope of the present invention that do not depart from appending claims and limited, can make variations and modifications.

[industrial applicability]

SOC measuring method of the present invention can be implemented as the form of the program of carrying out by various computing units, is recorded in then on the computer-readable medium. The computer-readable medium can comprise programmed instruction, data file, data structure etc. or their combination. Be recorded in programmed instruction on the medium and can design particularly or be configured to and use in the present invention, or under the technical staff's who offers the computer software field state, use. In addition, the computer-readable medium can comprise magnetizing mediums (such as hard disk, floppy disk and tape), optical medium (such as DVD), magnet-optical medium (such as floptical disk) and the hardware unit such as ROM, RAM and flash memory that is used for storage and performing a programme instruction. Medium can be for waveguide propagation medium, the metal wire propagation medium of the signal of transmission expression programmed instruction, data structure etc. or comprise the light propagation medium of carrier wave. Programmed instruction comprises the machine language code that forms by editing machine and the high-level language code to be carried out by computer that uses interpreter to form. In order to carry out operation of the present invention, hardware unit can be configured to by one or more software module operation, and vice versa.

Claims (17)

1. method of measuring the charged state of battery, this method may further comprise the steps:

Obtain current data, voltage data and temperature data by electric current, voltage and the temperature of measuring described battery;

By the described current data that adds up, calculate charged state SOCi based on electric current;

Use is represented the equivalent-circuit model of described current data, described voltage data and described battery to calculate open-circuit voltage OCV by circuit simply;

Use described temperature data and described OCV, calculate charged state SOCv based on voltage; And

In the time period of expectation, judge the current status of described battery, and use among described SOCv and the described SOCi at least one that the charged state of described battery is set.

2. method according to claim 1 wherein, is used the equivalent-circuit model of being represented described current data, described voltage data and described battery by circuit simply, and the step of calculating OCV comprises:

Use low-pass filter, described current data and described voltage data are carried out filtering;

By filtered current data and voltage data are applied to described equivalent-circuit model and adaptive digital filter, calculate the parameter of in described equivalent-circuit model, using; And

Use described parameter to calculate described OCV.

3. method according to claim 2, wherein, described low-pass filter is a third-order low-pass filter.

4. method according to claim 2, wherein, described equivalent-circuit model is represented by the circuit that uses resistance parameter R, current parameters I, capacitance parameter C, terminal voltage V parameter and VOC V parameter o.

5. method according to claim 2 wherein, is updated in the value of the described parameter of using in the described equivalent-circuit model by described adaptive digital filter.

6. method according to claim 1 wherein, is judged the current status of described battery in the time period of expectation, and at least one step that the charged state of described battery is set of using described SOCv and described SOCi comprises:

If described battery is in low current condition in the time period of described expectation, described SOCv is set to the charged state of described battery; And

If described battery is not in low current condition in the time period of described expectation, described SOCi is set to the charged state of described battery.

7. method according to claim 6, wherein, the time period of described expectation is 20 to 60 seconds, and the low current standard is 2A.

8. method according to claim 1 wherein, is used the equivalent-circuit model of being represented described current data, described voltage data and described battery by circuit simply, and the step of calculating OCV comprises:

Use is represented the integral model of the described equivalent-circuit model of described current data, described voltage data and described battery to calculate described OCV by described circuit simply.

9. device of measuring the charged state of battery, this device comprises:

The battery information acquisition unit, it measures electric current, voltage and the temperature of described battery, and obtains current data, voltage data and temperature data;

The electric current portion that adds up, it calculates charged state SOCi based on electric current by the described current data that adds up;

The OCV calculating part, it uses equivalent-circuit model to calculate open-circuit voltage OCV, represents described current data, described voltage data and described battery simply by circuit in this equivalence circuit model;

SOCv estimation portion, it uses described temperature data and described OCV to estimate charged state SOCv based on voltage; And

SOC is provided with portion, and it judges the current status of described battery in the time period of expectation, and uses among described SOCv and the described SOCi at least one that the charged state of described battery is set.

10. device according to claim 9, this device also comprises low-pass filtering portion, this low-pass filtering portion uses low-pass filter, and described current data and described voltage data are carried out filtering,

Wherein, described OCV calculating part will be applied to described equivalent-circuit model and adaptive digital filter through described filtered described current data of low-pass filtering portion and described voltage data, calculate the parameter of using in described equivalent-circuit model; And use described parameter to calculate described OCV then.

11. device according to claim 10, wherein, described low-pass filter is a third-order low-pass filter.

12. device according to claim 10, wherein, described equivalent-circuit model is represented by the circuit that uses resistance parameter R, current parameters I, capacitance parameter C, terminal voltage V parameter and VOC V parameter o.

13. device according to claim 10, wherein, described adaptive digital filter is updated in the value of the described parameter of using in the described equivalent-circuit model constantly.

14. device according to claim 9, wherein, if described battery is in low current condition in the time period of described expectation, then described SOC is provided with the charged state that the described SOCv of portion is set to described battery, and described in other cases SOCi is set to the charged state of described battery.

15. device according to claim 14, wherein, the time period of described expectation is 20 to 60 seconds, and the low current standard is 2A.

16. device according to claim 9, wherein, described OCV calculating part calculates described OCV by the integral model of described equivalent-circuit model.

17. a computer readable recording medium storing program for performing, its record are used for carrying out the program according to any one described method of claim 1 to 8.

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